The present invention relates to improvements in refrigerated beverage dispensers of the type involving a plurality of cooling plates, and, in one particular aspect, to novel and improved multi-bowl beverage dispensers wherein uniform and efficient chilling by way of separate flat cooling plates may be effected at low manufacturing cost through use of multi-turn sinuous coiling of evaporator tubing in which each turn extends serially across and part way around each plate, and back, in succession.
Apparatus for the counter-top display, cooling and dispensing of beverages has been known for some time in single-stand versions which mount more than one bowl or tank, and which thereby afford a convenient and compact means for exhibiting and serving different colorful soft drinks. Such apparatus has economically employed what is basically a single refrigeration system, including one motor-operated compressor and condenser, together with one evaporator split into different sections associated with cooling surfaces serving the different bowls. It has been observed that heat-exchange balance, as between two such bowls, should be benefitted by first arranging some evaporator coils, which are upstream in relation to the refrigerant supply, close to one bowl, and then locating intermediate coils close to another bowl, and then bringing the remaining downstream coils close to the first bowl. U.S. Pat. No. 3,060,702 describes and shows that kind of coil-splitting in relation to a twin-tank dispenser and in relation to two tiers of spiralled coil turns at each site. Similarly, U.S. Pat. No. 3,341,077 discusses and illustrates essentially the same thing, for like reasons, albeit in the context of tubing wound inside domes which project upwardly into two bowl compartments sharing a common wall. My U.S. Pat. No. 3,269,606 discloses a flat cooling plate to the underside of which is bonded a substantially flat spiral of evaporator tubing, and multiple-bowl dispensers of the present invention may usefully involve a plurality of such plates, although with the evaporator tubing arranged quite differently. Stacking of evaporator-coil sections, such as is resorted to in both of said U.S. Pat. Nos. 3,060,702 and 3,341,077, tends to complicate the winding, assembly, interconnecting and solder-bonding of the spiral or helical evaporator, and it adds height and bulk which is not readily accommodated unless one is willing to tolerate upwardly-projecting domes. Where there is stacking of spiral coils below flat cooling plates, there is also necessarily a less intimate heat-exchange relationship between some of such coils and the plates. Subdividing of the evaporator coiling into enough sections to make possible finer balance of cooling as between several bowls would at the same time entail manufacturing complexities and costs which would be highly unwelcome.